circulatory system Flashcards
what is the circulatory system?
it is a double system with 2 circuits joined together - in the right ventricle deoxygenated blood is pumped to the lungs to take in oxygen (then returns to the heart) - in the left ventricle oxygenated blood is pumped around to the other organs of the body, the blood gives up the oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
how dose the heart pump blood around the body?
the heart pumps blood by using muscle tissue located in the walls of the heart - the heart has valves to make sure blood flows the right way & to prevent backward flow - this is how the heart uses it 4 chambers
how are the 4 chambers used?
1) blood flows into the atria from the veca cava and the pulmonary vein 2) the atria contracts pushing blood into the venticals 3) the ventricles contract forcing the blood into pulmonary artery and the aorta , and out of the heart 4) blood then flows to the organs through arteries and returns through veins 5) the cycle repeats
what are the 3 blood vessels?
1) ARTERIES- carry blood away from the heart
2) CAPILLARIES- these are involved in exchanging materials at the tissue
3) VEINS- these carry the blood to the heart
what are the properties of arteries?
they have thick layers of muscle to make them strong and elastic fibers to allow them to stretch and spring back
what are the properties of capillaries?
carry blood under pressure. only one cell thick, very small hole down the middle, and have a nucleus of cells
what are the properties of veins?
veins bring blood back to the heart. veins connect from capillaries when blood is at low pressure, meaning the vein walls are thinner. They have a big hole down the middle to help with blood flow whilst also having valves to keep blood flowing the right way
how can u calculate the rate of blood flow?
rate of blood flow = volume of blood/ number of minutes
what is the role of red blood cells?
1) thwy carry oxygen from the lungs around the body 2) they have a large surface area in order to absorb more oxygen 3) they don’t have a nucleus - allows more room to carry oxygen 4) they contain a red pigment called haemoglobin 5) the lungs haemogoblin binds to the oxygen. In the body tissue the reverse happens
how do white blood cells work?
they fight against infection. some can change to engulf unwelcome microorganisms, others produces antibodies to fight microorganisms, as well and antitoxins to neutralise any toxins produced. Unlike read blood cells, white blood cells do have a nucleus
what do platelets help with?
playlets help with blood clots, they help by clotting around a wound to stop blood pouring out and stop microorganisms getting in
what is plasma?
the liquid that carries everything in blood, including platelets, red & white blood cells. it carries neutrino like glucose and amino acids, it carries carbon dioxide from the organs to the lungs, urea from the liver to the kidneys, hormones, proteins and antibodies + antitoxins produced by the white blood cells
